1. Field of the Invention
The present invention relates to collation of image data and, more particularly, to a pattern collation device for identifying linear graphic forms such as fingerprints and characters and a pattern collating method thereof, and a pattern collation program.
2. Description of the Related Art
As conventional devices for recognizing linear image patterns such as fingerprints and characters, the techniques are proposed in Japanese Patent Laying-Open (Kokai) No. Heisei 10-240932 and Japanese Patent Laying-Open (Kokai) No. Heisei 10-105703 in which using features points such as an end point and a branch point of a line, corresponding feature points are obtained and overlapped with each other for comparison.
Conventional techniques in which deformation of a graphic form is corrected to compare images have been proposed in Japanese Patent Laying-Open (Kokai) No. Heisei 02-187885, Japanese Patent Laying-Open (Kokai) No. Heisei 05-081412, Japanese Patent Laying-Open (Kokai) No. Heisei 06-004671, Japanese Patent Laying-Open (Kokai) No. Heisei 08-030783 and Japanese Patent Laying-Open (Kokai) No. Heisei 08-147411.
The conventional art, however, has the following shortcomings.
The conventional techniques recited in Japanese Patent Laying-Open No. Heisei 10-240932 and Japanese Patent Laying-Open No. Heisei 10-105703 have a problem that because the techniques employ a system of comparing graphic forms which are overlapped with each other as a whole, in such a case where a character is deformed or a fingerprint is deformed at the time of fingerprinting, the patterns can not be properly discriminated.
On the other hand, according to the conventional techniques recited in Japanese Patent Laying-Open No. Heisei 02-187885, Japanese Patent Laying-Open No. Heisei 05-081412, Japanese Patent Laying-Open No. Heisei 06-004671, Japanese Patent Laying-Open No. Heisei 08-030783 and Japanese Patent Laying-Open No. Heisei 08-147411, even when a graphic form is deformed, if the graphic form has the same deformation as a whole, correcting the deformation of the graphic form as a whole and comparing the same enables such a form to be coped with. However, in a case where each part has a different manner of deformation, an allowable difference should be increased to result in having inaccurate discrimination.